Grant Cohn: There are reasons to believe 49ers can upset Chargers

Everyone expects the 49ers to lose Sunday. Even the 49ers probably expect the 49ers to lose if they're being honest with themselves.

They're on the road again. They don't have their quarterback, Jimmy Garoppolo. And they're playing the Los Angeles Chargers, who do have their quarterback, Philip Rivers.

The 49ers are 10½-point underdogs. The biggest dogs in the league this weekend.

I'm picking the 49ers anyway. I have a crazy feeling about this game.

Here's why I'm picking the 49ers:

1. The Chargers defense is horrendous.

It has allowed 31 points per game this season.

It doesn't have starting cornerback Jason Verrett, who tore his Achilles during training camp. The 49ers can throw at Verrett's backup, Trevor Williams, as much as they want and have success.

The Chargers defense also doesn't have its best player, starting defensive end Joey Bosa. He's out with a bone bruise in his foot. The 49ers can run the ball at Bosa's backup, Isaac Rochell, as much as they want and have success.

The Chargers defense will improve when Bosa returns midseason. For now, it's vulnerable and the 49ers can take advantage of it.

2. The 49ers running game is terrific.

Alfred Morris is tough and reliable, and Matt Brieda is one of the most electric running backs in the NFL. They work well in tandem. Breida averages 8.6 yards per carry — tops in the league.

Collectively, the 49ers offense averages 152.7 rushing yards per game – second most in the NFL. Now that Garoppolo is out, the running game should become an even greater emphasis for the 49ers, and that's a good thing. They were too focused on passing when Garoppolo was healthy.

The Niners need to limit Beathard's exposure to the Chargers defense, limit how much he throws. They need to help him. They should try to run the ball 40 times against the Chargers.

That's a difficult goal to reach. But, if the 49ers reach it, they'll take pressure off Beathard, keep their defense fresh and probably win the game. Forty is a magic number.

3. C.J. Beathard is good enough.

He doesn't have Garoppolo's accuracy, velocity, quick release, footwork, confidence, experience, talent or general good looks.

But, Beathard is tougher than Garoppolo. And Beathard knows the 49ers offense better than Garoppolo, because Beathard has been on the team longer.

Beathard should have improved since last season despite his physical limitations. He should now make the correct audibles and pass-protection adjustments at the line of scrimmage before the play starts. And he should make smarter, quicker decisions in the pocket and read defenses better, too. He's not a rookie anymore.

The 49ers need Beathard to manage the game like a veteran, distribute the ball to all his different receivers and hand it off lots of times. Don't throw interceptions, fumble or do something wild like scramble up the sideline, stay in bounds, hit a defender, suffer a concussion and tear an ACL at the same time. The 49ers can't lose another quarterback. They're running out.

They shouldn't let Beathard throw more than 25 passes against the Chargers. That's another magic number.

4. The 49ers defense may not be as bad as it seems.

It was fantastic Week 1 on the road against the Minnesota Vikings. The 49ers defense gave up just 17 points in that game. But, the Vikings won anyway and finished with 24 points because Garoppolo threw a pick-six during the second half.

Week 2, the 49ers defense held the Lions to just 13 points through three quarters, but got tired and gave up 14 points during the fourth quarter, basically garbage time. The 49ers won anyway.

Week 3, they played a great Kansas City Chiefs offense in a road game that started at 10 a.m. Pacific Time. The entire 49ers team sleepwalked through the first half. After halftime when the 49ers finally woke up, the defense gave up only three points.

This week, the 49ers won't play at 10 a.m. Pacific Time. They will play at 1:25 and will be wide awake. And their excellent run defense will make the Chargers offense one-dimensional.

5. Philip Rivers is reckless.

Seventy-five percent of the time, he's great. One of the best of this generation. A future Hall of Famer.

The other 25-percent of the time, he almost singlehandedly loses the game for the Chargers.

Since 2011, Rivers has played 115 games, and has thrown at least two interceptions in 29 of them. So, he has a two-pick game roughly once every four weeks, or once a month.

In those 29 games since 2011 when Rivers has thrown at least two picks, the Chargers' record is 5-24. They usually don't overcome his careless mistakes.

I expect to see Careless Philip on Sunday.

This week, he probably studied the 49ers defense and licked his chops. He knows it gave up 35 points during the first half last week. Knows it hasn't intercepted a pass all season. Knows Richard Sherman and Jaquiski Tartt, the 49ers two best defensive backs, are injured. Sherman is out for Sunday with a strained calf, and Tartt probably won't play, either. The 49ers list him as 'doubtful' with a shoulder injury.

Rivers will have no conscience against the 49ers. He'll go bombs away instead of patiently checking down. He'll force the ball deep into coverage, the 49ers will pick him off twice and pull off an historic upset.

(Note: I'm probably wrong.)

Grant Cohn covers the 49ers and Bay Area sports for The Press Democrat and Pressdemocrat.com in Santa Rosa. You can reach him at grantcohn@gmail.com.